This invention is directed to a lamp which uses a solid fuel cartridge containing a solid fuel of low melting point (i.e., 80.degree. to 160.degree. F) which fixes the flame at a non-varying point. It combines the safety and handling convenience features of a solid fuel lamp or candle with the advantage of maintaining a fixed and non-varying flame position during its entire burning period. This is a feature of prime importance in the use of candles.
Candles using a wax as fuel and a wick to permit formation of a flame are commonly used for decorative purposes. In many cases, the wax is confined and contained in a glass or similarly appropriate vessel with a wick running through the approximate center. In use, the wick burns down slowly as the wax is consumed, which changes the position of the flame. Some types of construction avoid the change in flame height relative to the container by use of a spring-fed pressure plate to raise the candle to maintain the flame at a fixed height. In normal operation, the wick will maintain its height at a point just above the surface of the wax with the flame melting the wax beneath so that the liquid wax can be wicked to the burning area to maintain the flame. As the wax level drops, the wick burns down to the wax level. Beyond a certain point, the wick is difficult to relight with a hand-held match. In such cases, special tapers and lighting sticks must be used to avoid burning the fingers. It is common to see dropped matches in such candles where an attempt has been made to light the wicks.
There are also liquid fuel lamps. Such lamps have been developed over the ages for the burning of vegetable, animal, or mineral oils. The kerosene lamp is the liquid fuel lamp which had been widely used in recent generations before the broad distribution of electricity. The kerosene lamp has a liquid reservoir for the containment of kerosene and a wick which extends upward out of the reservoir to the place where the flame is held. A guard prevents the flame from traveling down the wick, and the height of adjustment of the wick above the guard controls the amount of available fuel supply and thus the amount of flame. When properly trimmed and adjusted, the wick in a kerosene lamp is not consumed. A major disadvantage of a liquid fuel lamp is the fire danger because, if the liquid is spilled or the reservoir is broken, the liquid fuel spreading in such manner represents a major fire hazard. For this reason, solid fuel is much preferred.